21344423231 has 4 divisors (see below), whose sum is σ = 21344715432. Its totient is φ = 21344131032.

The previous prime is 21344423189. The next prime is 21344423263. The reversal of 21344423231 is 13232444312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21344423231 - 2¹⁰ = 21344422207 is a prime.

It is a super-2 number, since 2×21344423231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21344423194 and 21344423203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344423531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71720 + ... + 218706.

It is an arithmetic number, because the mean of its divisors is an integer number (5336178858).

Almost surely, 2^21344423231 is an apocalyptic number.

21344423231 is a deficient number, since it is larger than the sum of its proper divisors (292201).

21344423231 is a wasteful number, since it uses less digits than its factorization.

21344423231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292200.

The product of its digits is 13824, while the sum is 29.

Adding to 21344423231 its reverse (13232444312), we get a palindrome (34576867543).

The spelling of 21344423231 in words is "twenty-one billion, three hundred forty-four million, four hundred twenty-three thousand, two hundred thirty-one".